Reports/reviews seems to indicate that the new 8-core MBPs are working fantastically.
The 2016 "only" has 16gb of RAM, right? With big still images I think you'll see improvements with 32gb ram in combination with better graphics card. But haven't used either (upgraded from 2012 retina to 2018 6-core)

But there's also rumours of a new 16" MBP coming out this fall. Might be worth holding out for unless you really urgently need a new one...